Bronchopulmonary dysplasia as a risk factor for asthma in school children and adolescents: A systematic review

Background: Bronchopulmonary dysplasia (BPD) is a chronic lung disease that mainly affects extremely pre-term infants, and remains the most common complication of prematurity. Several studies have shown that prematurity predisposes to the development of asthma in school children and adolescents. Nevertheless, it is not clear to what extent a history of BPD involves an additional risk. Methods: A systematic review of studies assessing the association between BPD and asthma in school-children and adolescents was made. A literature search was carried out in the MEDLINE and EMBASE databases to retrieve articles published between 1 January 2000 and 31 August 2016. Results: A total of 17 studies comprising 7433 patients were included in the review. There was considerable heterogeneity in the definitions of BPD and asthma among studies. Overall, the prevalence of asthma was higher in children and adolescents with a history of prematurity and BPD compared with those who did not develop BPD. However, in only one of the studies did this difference reach statistical significance. The main limitation of this review was potential bias due to the lack of adjustment for confounding factors between exposure (BPD) and outcome (asthma) in most of the studies. Conclusion: Based on the studies reviewed, it cannot be argued that BPD, as an independent factor of prematurity, increases the risk of asthma defined by clinical parameters in schoolchildren and adolescents. Further studies of greater methodological quality and homogeneous diagnostic criteria of BPD and asthma are needed for improved assessment of this association. (C) 2017 SEICAP. Published by Elsevier Espana, S.L.U. All rights reserved.